Calculus of variations.
Gelʹfand, I. M.(Izrailʹ Moiseevich)
Silverman, Richard A.
Fomin, S. V.(Sergeĭ Vasilʹevich)
Englewood Cliffs, N.J.,
[1963]
Joint authors: Izrail Moiseevich Gel'fand and Sergei Vasil'evich Fomin.